A flow criterion for oriented polyethylene in tensile deformation

Tensile test specimens were cut from high density polyethylene that had been fully cold drawn. The angle between the tensile axis and the draw direction was varied from 30 to 80° and the specimens were deformed at temperatures between 0 and 120° C. Deformation beyond yield occurred without any work hardening and could be described in terms of a flow criterion. The parameters of the flow criterion were found to be slightly dependent upon the initial orientation angle, but highly temperature sensitive.